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This paper introduces the concept of interpolation consistency. It is claimed that this property is an essential one for splines that are intended for use in Computer Aided Design. Consistency is defined as the property ...

User friendliness is one of the unresolved problems in CAD systems. There are many possible directions for improving user friendliness. Understanding of the modeling process is one of the most important directions. It is ...

Given a set of pairwise disjoint planar polygonal faces with altogether N edges in the three-dimensional space. Let k be the number of intersection points of the projections of the edges in a projection plane, 0 < k < ...

A new algorithm for contour-plotting is introduced. The input function, tabulated or in a subroutine description, is approximated by an interpolation function. The contours of this approximating function are drawn piecewise ...

When simulating a moving observer or sensor in a 3D scene which contains a large number of objects, only the objects lying in the field of view or of interaction, named the local data base, have to be taken into account ...

This paper describes a new antialiasing method when a z-buffer is used. Good quality antialiasing is achieved in spite of unavoidable approximations. Compared to an ordinary z-buffer, only a little extra memory space and ...

A spatial metric for adapting the level of detail in a modelled object to achieve a convincing degree of realism on a display is formulated and illustrated with a simple implementation. This spatial metric is designed to ...

Object orientation and concurrency are inherent to computer animation. Since the pieces of an animation can come from various media such as computer-generated imagery, video, and sound, the case for object orientation is ...

This paper presents the design of THESEUS, a system for programming graphical user interfaces especially targetted at the area of software engineering. Starting with the special needs and requirements that arise in this ...

A production system based User Interface Management System (UIMS) is discussed. The UIMS, called Viz, has been designed and implemented in a windowed workstation environment, and (a) capitalises on the graphical facilities ...

In this paper, we introduce three types of shape control parmeters (tension, bias, and continuity) into the modelling of free-form surfaces composed of bicubic Bernstein-Bezier patches. This is an extension to surfaces of ...

The Clockworks is an object-oriented computer animation system developed at RPl's Center for Interactive Computer Graphics (CICG). The Clockworks has the ability to model and graphically simulate complex 3-D engineering ...

Novel and efficient algorithms have been developed in order to display on a raster scan device some basic 3D models used in computer-assisted chemistry. They allow, among other things, the construction and manipulation of ...

This paper describes a general framework for the formal specification of modular graphics systems. The approach is illustrated by an example taken from the Graphical Kernel System (GKS) and uses the Z specification notation.

The Programmer’s Hierarchical Interactive Graphics System (PHIGS), currently under development by ISO, is a specification of a set of functions for device-independent computer graphics programming, supporting dynamic ...

To exploit the full capabilities of raster graphics, two and three dimensional drawing primitives should play a preponderant role in the specification of a graphics standard. In addition there should be facilities for ...

The output pipeline of GKS-3D/PHIGS isexamined to find some possible points where the implementation could be improved to raise efficiency while remaining strictly within the scope of the Standards. Some interesting results ...

In both scan conversion and clipping, algorithm for dealing with polygons are generally presented independently of those for vectors, although many of the operations performed are similar. This paper shows how polygon ...

Algorithms are presented for the determination of whether a given point E<sup>2</sup> in is interior to, exterior to or on an arbitrary polygonal boundary and for the determination of whether a point in E <sup>3</sup> is ...

There is a growing need for fast high-quality display of solid objects. Recently-developed custom-VLSI hardware offers high-speed display but lacks the flexibility and processing power at the pixel level to sustain the ...